How do I make dark oak material in BLENDER
You can easily recolor any image texture using nodes.  




Start with a suitable wood texture. Choose by pattern, you'll adjust the color.
There are many free ones on the Interwebs (god, i love that word).
I used this free one from Poliigon 
Connect it into the Base color input
Adjust colors using RGB curves/Hue saturation node... whatever you like.
Blender offers many Color nodes just for this.
Just connect the node in front of your image texture like in my image.




Source image texture


Note:
If you're a beginner I reccomend BlenderGuru's Donut tutorial.
You'll learn everything you need there :).